IPs can be masked, or he got another computer, or he's posting from somewhere else, etc., etc., etc.
JFS makes several comments over at SCI about how Doc says that he should charge for his plays. Then a little comment sets him off and he says he won't post there anymore. Keep in mind that he's a mod over there and can ban the guy or delete the post. Then, mysteriously, a thread shows up in Site Promos gathering an email list. Think, Kojak. Think.
Look at the writing style. JFS always capitalized DOC and he uses quotations a lot. Sentence and paragraph structure are identical. There is one other tell that I'm waiting for him to use that's a dead giveaway.
Also, he has posted here with a troll before. The last time was before SCI started up.
It doesn't take a rocket scientist.